Auditory prostheses, such as cochlear implants, include an implantable portion having a stimulating assembly with an implanted coil and an external portion having a coil, speech processing hardware and software, as well as a battery. Recipients of such devices desire the external portion to be as light and small as possible, both for comfort and unobtrusiveness. Reducing the size of such external portions is complicated however, since positioning the various components, e.g., the batteries and coil, closer to each other can reduce the quality of signals sent between the external and implanted coils.